Effect of light absence or attenuation on biaxial flexural strength of dual-polymerized resin cements after short- and long-term storage.

OBJECTIVE: To evaluate whether biaxial flexural strength (BFS) of dual resin cements is affected by light absence or attenuation, storage time, or cements' chemical nature. MATERIALS AND METHODS: One hundred and twenty disk-shaped specimens were made from each cement (non-self-adhesive cement and self-adhesive cement) using Teflon molds on a controlled temperature surface (35°C). Specimens were polymerized as follows (N = 30): self-cured, directly light-cured, light-cured at a distance of 6 mm between the light tip and the specimen, and through a 6-mm thick composite resin barrier (indirectly light-cured). Each group was divided (N = 10) for storage purposes (15 minutes, 24 hours, and 6 months). Specimens were placed into a biaxial-flexure jig and a vertical load was applied until failure. The BFS values were subjected to generalized linear models statistical analysis and Weibull distributions (α = 0.05). RESULTS: After 15 minutes aging, neither material achieved enough polymerization to perform the BFS test when polymerized using the self-curing mode. The self-adhesive product demonstrated much lower variation in strength with storage time than did the non-self-curing cement. CONCLUSIONS: Attenuated/light-curing reduced BFS values only for 15-minutes storage period for both materials. Flexural strength of the self-adhesive cement was less affected by light absence/attenuation and storage time. CLINICAL SIGNIFICANCE: Biaxial flexural strength of a self-adhesive resin cement is less sensitive to variation in light application and storage time than is a non-self-adhesive cement.

RNA-Seq and metabolic flux analysis of Tetraselmis sp. M8 during nitrogen starvation reveals a two-stage lipid accumulation mechanism.

To map out key lipid-related pathways that lead to rapid triacylglyceride accumulation in oleaginous microalgae, RNA-Seq was performed with Tetraselmis sp. M8 at 24h after exhaustion of exogenous nitrogen to reveal molecular changes during early stationary phase. Further gene expression profiling by quantitative real-time PCR at 16-72h revealed a distinct shift in expression of the fatty acid/triacylglyceride biosynthesis and ß-oxidation pathways, when cells transitioned from log-phase into early-stationary and stationary phase. Metabolic reconstruction modeling combined with real-time PCR and RNA-Seq gene expression data indicates that the increased lipid accumulation is a result of a decrease in lipid catabolism during the early-stationary phase combined with increased metabolic fluxes in lipid biosynthesis during the stationary phase. During these two stages, Tetraselmis shifts from reduced lipid consumption to active lipid production. This process appears to be independent from DGAT expression, a key gene for lipid accumulation in microalgae.

Metabolic Reconstruction of Setaria italica: A Systems Biology Approach for Integrating Tissue-Specific Omics and Pathway Analysis of Bioenergy Grasses.

The urgent need for major gains in industrial crops productivity and in biofuel production from bioenergy grasses have reinforced attention on understanding C4 photosynthesis. Systems biology studies of C4 model plants may reveal important features of C4 metabolism. Here we chose foxtail millet (Setaria italica), as a C4 model plant and developed protocols to perform systems biology studies. As part of the systems approach, we have developed and used a genome-scale metabolic reconstruction in combination with the use of multi-omics technologies to gain more insights into the metabolism of S. italica. mRNA, protein, and metabolite abundances, were measured in mature and immature stem/leaf phytomers, and the multi-omics data were integrated into the metabolic reconstruction framework to capture key metabolic features in different developmental stages of the plant. RNA-Seq reads were mapped to the S. italica resulting for 83% coverage of the protein coding genes of S. italica. Besides revealing similarities and differences in central metabolism of mature and immature tissues, transcriptome analysis indicates significant gene expression of two malic enzyme isoforms (NADP- ME and NAD-ME). Although much greater expression levels of NADP-ME genes are observed and confirmed by the correspondent protein abundances in the samples, the expression of multiple genes combined to the significant abundance of metabolites that participates in C4 metabolism of NAD-ME and NADP-ME subtypes suggest that S. italica may use mixed decarboxylation modes of C4 photosynthetic pathways under different plant developmental stages. The overall analysis also indicates different levels of regulation in mature and immature tissues in carbon fixation, glycolysis, TCA cycle, amino acids, fatty acids, lignin, and cellulose syntheses. Altogether, the multi-omics analysis reveals different biological entities and their interrelation and regulation over plant development. With this study, we demonstrated that this systems approach is powerful enough to complement the functional metabolic annotation of bioenergy grasses.

Genomic characterization of the uncultured Bacteroidales family S24-7 inhabiting the guts of homeothermic animals.

BACKGROUND: Our view of host-associated microbiota remains incomplete due to the presence of as yet uncultured constituents. The Bacteroidales family S24-7 is a prominent example of one of these groups. Marker gene surveys indicate that members of this family are highly localized to the gastrointestinal tracts of homeothermic animals and are increasingly being recognized as a numerically predominant member of the gut microbiota; however, little is known about the nature of their interactions with the host. RESULTS: Here, we provide the first whole genome exploration of this family, for which we propose the name "Candidatus Homeothermaceae," using 30 population genomes extracted from fecal samples of four different animal hosts: human, mouse, koala, and guinea pig. We infer the core metabolism of "Ca. Homeothermaceae" to be that of fermentative or nanaerobic bacteria, resembling that of related Bacteroidales families. In addition, we describe three trophic guilds within the family, plant glycan (hemicellulose and pectin), host glycan, and α-glucan, each broadly defined by increased abundance of enzymes involved in the degradation of particular carbohydrates. CONCLUSIONS: "Ca. Homeothermaceae" representatives constitute a substantial component of the murine gut microbiota, as well as being present within the human gut, and this study provides important first insights into the nature of their residency. The presence of trophic guilds within the family indicates the potential for niche partitioning and specific roles for each guild in gut health and dysbiosis.

Plant genome-scale modeling and implementation.

Considerable progress has been made in plant genome-scale metabolic reconstruction and modeling in recent years. Such reconstructions made it possible to explore metabolic phenotypes through appropriate model formulation and optimization methods. As a result, plant genome-scale modeling has increasingly attracted interest from the plant research community. In this chapter, the first generation of plant genome-scale metabolic reconstructions is presented, along with the important concepts behind model and constraint formulation. A brief protocol describing the use of constraint-based reconstruction and analysis (COBRA) Toolbox in flux simulation and model modification is provided. This is followed by a presentation of metabolic constraints required to generate fluxes in AraGEM using COBRA that describe photosynthesis, photorespiration, and respiration, respectively. Overall, plant genome-scale modeling is a powerful approach that is accessible and readily adopted.

Early intravitreal treatment of endogenous bacterial endophthalmitis.

BACKGROUND: There are currently no standardized treatment guidelines for endogenous bacterial endophthalmitis. We report the long-term outcomes of early intravitreal treatment of endogenous bacterial endophthalmitis, defined as intravitreal and systemic antibiotics administered within 24 h of diagnosis, with conservative use of pars plana vitrectomy. DESIGN: Interventional retrospective case series. PARTICIPANTS: Consecutive patients treated for culture-proven endogenous bacterial endophthalmitis between 2001 and 2008 at the Weill Cornell Medical Center. METHODS: The clinical records of 18 eyes from 13 patients were reviewed. MAIN OUTCOME MEASURES: Visual acuity. RESULTS: Mean age at presentation was 61 (25-85) years. All patients had underlying medical conditions. Extraocular infectious foci were identified in nine (69%) patients, with endocarditis being the most common. Gram-positive organisms were identified in 12 (92%) patients, including five with methicillin-resistant Staphylococcus aureus. No cases were misdiagnosed. Final visual acuities of better than 6/120 and counting fingers were achieved in 6 (55%) and 7 (64%) of 11 eyes, respectively. Longer time between onset of ocular symptoms and intravitreal antibiotic injection correlated with worse visual outcomes (P < 0.05) and was associated with mortality (P < 0.05). Mortality was also associated with methicillin-resistant S. aureus infection (P < 0.05). Of those with follow up longer than 1 year, retinal detachment developed in 3 of 10 eyes (30%) after the acute infection, and cataract developed in 6 of 9 (67%) phakic eyes. Mean follow up was 146 (4-313) weeks. CONCLUSIONS: Intravitreal antibiotics for endogenous bacterial endophthalmitis administered within 24 h to supplement immediate systemic antibiotics may provide a relatively favourable visual prognosis.

"Immuknow" to measurement of cell-mediated immunity in renal transplant recipients undergoing short-term evaluation.

The aim of this preliminary, observational study was to evaluate the value of ImmuKnow (IK), a new tool to measure the net state of immunefunction among renal transplant recipients, in correlation with clinical and laboratory data among unselected renal transplant recipients. Forty-nine recipients of mean age of 51 years were enrolled and followed for 1 year after transplantation. All subjects received the same immunosuppressive strategy with basiliximab induction and tacrolimus, mycophenolate mofetil and steroid maintenance therapy. Samples for IK were collected before transplantation as well as at 7, 14, 21 and 42 days and after 3, 6, and 12 months. There were 54 samples with IK <225 ng/mL, 201 samples with normal IK values, and 135 samples with >525 ng/mL. We divided recipients into 3 groups with respect to their basal IK values: Group 1 (Gr1; IK <225 ng/mL); Group 2 (Gr2; normal values of IK between 226 and 524 ng/mL); and Group 3 (Gr3; IK >525 ng/mL). At 1 year, we observed a significant difference among IK values at the start and the end of the study: Gr1 vs Gr2, P<.0001; Gr2 vs Gr3, P<.06 and Gr 1 vs Gr 3, P<.01). We observed reduced IK values to predict an increased risk of infection, particularly with cytomegalovirus (CMV) replication while higher IK value did not correlate with an increased risk of acute rejection episodes. Reduction of serum creatine levels occurred within 1 year in all groups (P<.005), but there was a significant difference between Gr 2 versus Grs 1 and 3 (P<.0001 and P<.0005, respectively). There findings suggested that more stable IK values were associated with clinical quiescence and laboratory stability. In conclusion, our preliminary analysis showed a beneficial capacity of this assay to represent the global depression of the immune system. We noted that reduced IK values, as a sign of excessive immunosuppressive therapy, were associated with an increased risk of infection. We did not confirm the predictive value of higher IK values for an increased risk of an acute rejection episode.

Methylenetetrahydrofolate reductase gene mutation in a 16-year-old girl with combined central retinal vein occlusion/cilioretinal artery occlusion.

PURPOSE: This case report describes combined central retinal veincilioretinal artery occlusion in a 16-year-old healthy girl. To our knowledge, our patient is the youngest described so for in the MEDLINE literature. METHODS: The patient underwent a full history, physical examination, and extensive laboratory studies to determine the potential risk factors leading to her vascular occlusion. RESULTS: Her family history was significant for multiple miscarriages and early cerebrovascular events. Laboratory testing revealed a compound heterozygous mutation (C677T and A1298C) in the methylenetetrahydrofolate reductase (MTHFR) gene and an elevated factor VIII level. As a result of her ocular occlusive event, abnormal hypercoagulable findings, and family history, the hematologist treated her with folate and warfarin. She has had no further ocular or systemic thrombotic events to date. CONCLUSION: The combination of the compound heterozygous C677TA1298C MTHFR mutation and an elevated factor VIII level may lead to an increased thrombotic tendency and may have resulted in combined central retinal veincilioretinal artery occlusion in an otherwise healthy 16-year-old girl.

Structure and function evaluation (SAFE): II. Comparison of optic disk and visual field characteristics.

PURPOSE: To evaluate the relationship between glaucomatous structural damage to the optic nerve and development of visual field loss with standard automated perimetry (SAP) and short wavelength automated perimetry (SWAP). DESIGN: Cohort study. METHODS: Patients with elevated intraocular pressure and normal SAP visual fields were enrolled in this prospective study. Stereo optic disk photographs, SAP, and SWAP visual fields were obtained annually over a period of 4 or more years. Trained readers evaluated baseline and follow-up optic disk photographs for evidence of glaucomatous damage. Standard automated perimetry and SWAP examinations were evaluated according to previously validated criteria for development of confirmed visual field changes. RESULTS: Two-hundred ninety-five subjects (479 eyes) were enrolled. Following masked assessment of stereo photographs by an optic disk reading center, 272 of the 479 eyes were judged to have glaucomatous optic neuropathy at the time of study entry. Depending on the criteria employed, approximately 10% to 17.5% of all eyes developed confirmed visual field loss for SAP (conversions). Of the conversions, 75% to 80% had baseline glaucomatous optic disk damage, whereas normal and glaucomatous optic disks were equally divided (50%) among the nonconversion eyes. This difference was statistically significant (P <.003). Depending on the criteria employed, 4% to 12% of the eyes had confirmed SWAP deficits at baseline, and 4% to 8% developed confirmed SWAP defects at a follow-up examination. There was a greater percentage of eyes with a glaucomatous optic neuropathy in the group with SWAP deficits (75%-100%) than for those eyes in which SWAP remained normal (45%-60%). Some of these differences were statistically significant (P <.05). CONCLUSIONS: A strong relationship exists between glaucomatous optic disk damage at study entry and the subsequent development of a confirmed glaucomatous SAP visual field defect. A higher percentage of glaucomatous optic disks were also found in patients with SWAP deficits at baseline and in those who later developed SWAP deficits. These findings support the premise that a glaucomatous optic disk is predictive of the subsequent development of glaucomatous visual field loss.